The present invention relates to a device for the linear treatment, such as sewing, along a line whose direction remains substantially tangent to a curved edge of fabric or other supple piece in sheet form. The device comprises a linear treatment machine with a fixed station having a fixed point of treatment; a guiding and driving device to make the fabric pass through the point of treatment and to move the zone of the piece which is being treated with respect to the treatment machine along a predetermined treatment axis; a work table extending around the driving device and situated substantially above the point of treatment for supporting the piece during the treatment; and a correcting device comprising means for detecting the presence of the piece in a detection zone of the work table situated upstream of the point of treatment and at least on one side of the axis of treatment, and a re-centering means controlled by the detection means for displacing the fabric substantially transversely with respect to the axis of treatment and in the appropriate direction as a function of the presence of the fabric on at least one point of the detection zone, in order that the fabric be treated by the treatment machine along a line which extends substantially in parallel to the curved edge of the fabric.
In an installation of this type described in French Pat. No. 2,252,008, the re-centering means comprise a roundabout, rotatable above the work table and the frame of the treatment machine, the roundabout comprising a plurality of shoes adapted to come in resting contact on the fabric being treated.
Such a device is complicated and requires the piece of fabric or other material to be kept flat and without folds on the work table during the treatment.